fragment; multiple DNA samples drawn from nine coral species and four different reef locations are PCR screened for archaeal and bacterial amoA genes, and archaeal amoA gene sequences are obtained from five different species of coral collected in Bocas del Toro, Panama. The 210 coral-associated archaeal amoA sequences recovered in the study are broadly distributed phylogenetically, with most only distantly related to previously reported sequences from coastal/estuarine sediments and oceanic water columns

particulate methane monooxygenase and ammonia monooxygenase are evolutionarily related enzymes despite their different physiological roles in these bacteria. Nitrosococcus oceonus AmoA shows higher identity to PmoA (methane monooxygenase) sequences from other members of the gamma-proteobacteria than to AmoA sequences

two copies of amoA (amoA1 and amoA2), they differ by one nucleotide. Either copy of amoA is sufficient to support growth when the other copy is disrupted. Inactivation of amoA1 results in slower growth; two copies of amoA (amoA1 and amoA2), they differ by one nucleotide. Either copy of amoA is sufficient to support growth when the other copy is disrupted. Inactivation of amoA2 does not results in slower growth

AmoC3 is involved in the heat shock response. AmoC3 functions in part as an alternative stress response subunit that mediates the stability of ammonia monooxygenase during heat shock and other conditions that cause membrane stress or instability of the ammonia monooxygenase holoenzyme

nitrification is a fundamental process in the marine nitrogen cycle that makes fixed nitrogen available in the form of nitrite and nitrate to primary producers and for denitrification and anaerobic ammonium oxidation. Nitrification results from the combination of two processes: ammonia oxidation and nitrite oxidation. The ammonia oxidation process starts with the oxidation of ammonia to hydroxylamine, which is catalyzed by ammonia monoxygenase, AMO

Nitrosopumilus maritimus is adapted to grow on ammonia concentrations found in oligotrophic open ocean environments, far below the survival threshold of ammonia-oxidizing bacteria. The archaeal AMO oxidizes ammonia to hydroxylamine similar to the bacterial pathway

ammonia monooxygenase of Nitrosomonas europaea catalyzes the oxidation of alkanes (up to C8) to alcohols and alkenes (up to C5) to epoxides and alcohols in the presence of ammonium ions. Straight-chain, N-terminal alkynes (up to C10) all exhibit a time-dependent inhibition of ammonia oxidation without effects on hydrazine oxidation

identification of organic oxidation products and comparison of the reactivities of monohalogenated ethanes and n-chlorinated C1 to C4 alkanes for oxidation by whole cells of Nitrosomonas europaea. The dehalogenating potential of the ammonia monooxygenase in Nitrosomonas europaea may have practical applications for the detoxification of contaminated soil and groundwater

the addition of CuCl2 to cell extracts results in 5- to 15-fold stimulation of ammonia-dependent O2 consumption, ammonia-dependent nitrite production, and hydrazine-dependent ethane oxidation. Two populations of AMO in cell extracts. The low, copper-independent (residual) AMO activity is completely inactivated by acetylene in the absence of exogenously added copper. The copper-dependent (activable) AMO activity is protected against acetylene inactivation in the absence of copper. However, in the presence of copper both populations of AMO are inactivated by acetylene

stimulates in vitro. Loss of enzyme activity upon lysis of Nitrosomonas europaea results from the loss of copper from the enzyme, generating a catalytically inactive, yet stable and activable, form of the enzyme

two populations of AMO in cell extracts. The low, copper-independent (residual) AMO activity is completely inactivated by acetylene in the absence of exogenously added copper. The copper-dependent (activable) AMO activity is protected against acetylene inactivation in the absence of copper. In the presence of copper both populations of AMO are inactivated by acetylene

stoichiometry, ammonia and oxygen uptake, and catalytic kinetics of ammonia oxidation using an optimized microrespirometry setup, overview. The ammonia oxidation kinetic does not obey a classical Michaelis-Menten model

AmoB-protein is located in all genera (Nitrosomonas, Nitrosospira, Nitrosococcus, Methylococcus) on the cytoplasmic membrane. In cells of Nitrosomonas and Nitrosococcus additional but less AmoB-labeling is found on the intracytoplasmic membrane

AmoB-protein is located in all genera (Nitrosomonas, Nitrosospira, Nitrosococcus, Methylococcus) on the cytoplasmic membrane. In cells of Nitrosomonas and Nitrosococcus additional but less AmoB-labeling is found on the intracytoplasmic membrane

AmoB-protein is located in all genera (Nitrosomonas, Nitrosospira, Nitrosococcus, Methylococcus) on the cytoplasmic membrane. In cells of Nitrosomonas and Nitrosococcus additional but less AmoB-labeling is found on the intracytoplasmic membrane

AmoB-protein is located in all genera (Nitrosomonas, Nitrosospira, Nitrosococcus, Methylococcus) on the cytoplasmic membrane. In cells of Nitrosomonas and Nitrosococcus additional but less AmoB-labeling is found on the intracytoplasmic membrane

the membrane-bound, active-site-containing 27000 Da polypeptide of ammonia monooxygenase undergoes an aggregation reaction when cells or membranes are heated in the presence of SDS-PAGE. The aggregated protein can be returned to the monomeric state by incubation at high pH in the presence of SDS. Strongly hydrophobic amino acid sequences present in ammonia monooxygenase are responsible for the aggregation phenomenon

cells of Nitrosomonas europaea may be able to support two types of ammonia monooxygenase activity. One of these types appears to provide a base level of enzyme activity which is largely insensitive to changes in the available NH3 concentration. This is the activity which is observed at the start of each incubation and the level to which the cells returned after they underwent an initial stimulation of activity and a subsequent decline. The second type of ammonia monooxygenase can be increased in response to increases in NH3 availability and can be rapidly decreased in response to NH3 limitation. These two differentially regulated forms of enzyme activity could be particularly useful to Nitrosomonas europaea for a rapid response to transient fluctuations in ammonia availability and still allow the organism to maintain a basal level of ammonia monooxygenase activity to generate energy for both cell maintenance and the rapid de novo synthesis of protein once ammonia becomes available

when Nitrosomonas cells are grown with pyruvate as the electron donor and nitrite as the electron acceptor under anoxic conditions, the amount of ammonia monooxygenase in the cells decreases. After about 2 weeks, ammonia monooxygenase is no longer detectable in the denitrifying cells

identification of organic oxidation products and comparison of the reactivities of monohalogenated ethanes and n-chlorinated C1 to C4 alkanes for oxidation by whole cells of Nitrosomonas europaea. The dehalogenating potential of the ammonia monooxygenase in Nitrosomonas europaea may have practical applications for the detoxification of contaminated soil and groundwater

the functional gene amoA is used to compare the diversity of ammonia oxidizing bacteria in the water column and sedimentwater interface of the two freshwater lakes Plusssee and Schoehsee and the Baltic Sea